Process for the treatment of leucite and other sodium and potassium silicates with lime for the purpose of extracting potassium or sodium and aluminum values



Patented Mar. 8,1927.

UNITED ,sT rs ATEN "OFFICE;

' rum JOURDAN, or noun,- I'rA Y.

rmcnss ronrnn TREATMENT or mm-m ornna sonrum am) rorassium sonnm am) summon vanuns.

Io Drawing. Applicationfiied December 27, 1924,

Y It is known that,if leucite is mixed with lime or with calcium carbonate and the mixture is heated lintil itreaches' the melting temperature, there is obtained therefrom a pasty or liquid mass, which, when certain determined proportions of lime and leuciteand a certain'duration of the action are maintained, after having been cooled and powdered and upon being lixiviated,

10 preferably with warm water sets free aluminum and potassium in the form :of' aluminate of potassium. v

The application of the same process in v connection with sodium leucite permits one to obtain soda and aluminum in the form of aluminate of sodium.

In general the rocess may also be more" or less suitably a opted in connection with other ores consisting substantially of sili-. cates of aluminum and of potassium or of.

lumps is burnt in a furnace of any conve'nient kind, such as lime furnace, reverberatory furnace, rotary furnace etc., capable of raising the temperature of the material up to 1000 or 1400 C. y The melting is facilitated by adding to the mixture of lime and leucite a suitable 40 flux,-'and it has been ascertained that the use of carbonate of iron in the proportion venient.

As flux, instead of carbonate of iron, may

of 5 to 15% has proved to be very conalso be employed ferric oxide Fe O,, but inthis case it is necessary to add a small quantit of coal. 4

The walls of.the furnace are to be provided with a lining of lime, magnesia or an other refractory alkaline material. e 1zc escapin from the furnace-are eollec andjfilte for the purpoeeef recarbonate into lime.

by V fiid diiferencesascertained are very great inasmuch as the yield. of the material BILIGATES WITH- LIME FOR THE PURPOSE OF' EXTBACTING POTASSIUM OR Serial 1%. 7524;455, and in Italy December as, 1923.

covering the potassium that may have volatilized and of utilizing the carbonic acid contained therein. i

After melting the product upon having been cooled down is either ground or, when leaving the furnace, it is powdered by means of a blowingaction performed with air free from carbonic acid; I

The powder thus obtained is lixiviated, preferably by treating it' hot and by employing processes permitting one to secure the greatest saturation with the aluminate of potassium, the wasli'water being again utilized for the lixiviation'of fresh material.

The solution of 'aluminate separated through filtration and suitably enriched is treated with carbonic acid anhydride, and

in connection with this treatment may be utilized the carbonic acid anhydride produced during the transformation of calcium- In this way is ob tained the formation of carbonate of potassium or of carbonate of sodium, i a sodium leucite has been treated, and the precipitation'of alumina in a pure state, which is separated through filtration.

The economical value of the aforesaidprocas, from the industrial standpoint, chiefly depends upon the yield of potash obtainable through lixiviation of the owder of the molten material, and upon t e cost involved with powdering this material.

For the purpose of or even entirely eliminating the cost involved with the powdering operation'it would appear to be convenient, instead of grin the molten material after cooling, to pow er it by causing it to undergo a blowing action while it is still in a liquid condition when leaving the furnace. V

, However, practical experiments have roved that the powdering process performed by adoptin the blowing action from the standpoint of the yield is not convenient inasmuch as it has been ascertained that the same is always considerably lower than the yield of solublepotash which is obtained by firstly c the molten product and then ding it after solidification.

powdered through-blowing action amounts and then cooling takes to about 12%, while the yield of the cast ground material surpasses even 90%. v A more accurate investigation of the circumstances exerting aninfluence u n the value of the yield has proved that t e yield of soluble potash is so much the greater the slower the cooling operation proceeds. Conkilograms by coolingl uentl if the wdering is performed :lii 'ough bIowing a dtion, in which case the place quite suddenly and immediately, the yield is extremely low and nearly naught. In fact, the molten product thus cooled assumes a glassy appearance and through lixiviation it no longer supplies any soluble aluminate. a

As far as concerns the product molten and cooled stated' above, been ascertained that the quantity of soluble aluminat'e which may be obtained increases by the slowing down of the cooling action and consequently the cast lumps have a greater volume. the samples of a lump mould or in a furnace it as already stated above, samples taken out from mass is greater than with the samples taken from the periphery, that is with those contacting with the walls where the cooling actionproceeds more-speedily.

Moreover, with these tests has been ascer- Upon testing cooled down in a will be found'that, the yield with the the center of the down after casting, it has, as already I blowing action.

tained another very important and unexpected circumstance, namely that the material cast in thick masses and cooled down slowly falls into powder by itself and that the naturally powdered quantity is so much the greater the slower proceeds the cooling action. a

When treating masses of av few hundred them down slowly in two or three days, e whole material falls com letely into powder and the yield of solu le potash rises as far as to reach about 95%. v

Consequently, it is unnecessary, even from the standpoint of the milling expenses, to take into consideration the convenience of powdering. the material through a sudden cooling operation performed by means of a The process of producing potash and alumina from leucite treated with lime at a high temperature, until the mixture is caused to melt, which process consists in so casting the molten product that it will form big lumps, and then cooling these down in such a way as to cause them to disintegrate into a powdery mass.

In testimony whereof I haveiafiixed my signature.

FELIX JOURIHDAN. 

